You don't, those structures are generated differently and not using structure blocks. I wrote a guide about structure blocks and their overall usage, you can find that
Due to personal reasons I need a serious distraction right now so yah, lets do another small mega guide
The 4 new zecret block variants
2 new hidden blocks
Most regular blocks in Minecraft can be easily obtained if you got access to gamemode 1 (Creative mode). All but a few hidden blocks... There's the command block (id 137 => minecraft:command_block) and its two counterparts the chain_command_block (id 211) and the repeating_command_block (id 210). We have a barrier block (id 166 => minecraft:barrier) and finally you also can't obtain a mob spawner through your creative inventory (id 52 => minecraft:mob_spawner).
Edit: And I forgot my all time favorite: farmland (id 60 => minecraft:farmland)!
And now we have 2 more hidden blocks: the Structure block (id 255 => minecraft:structure_block) and the Structure void (id 217 => minecraft:structure_void). The fun part is that unlike the command block there's only 1 structure block, even though it can show up as different counterparts (see picture above).
Let me tell you guys: these are totally awesome.
What can a structure block do?
Simply put: it can save and load structures. And more, but the information regarding the 'data block' is still very obscure. And it even changed between the official MC 1.10 release and now. So I won't be talking about the data block, only the other variants: the save, load and corner structure block.
On my redstone world I've build one large metal pyramid and placed 2 beacons on top in order to give me speed II and jump boost II. The problem is simple: when I get out of reach from the pyramid then I lose my status effects. I tried setting up some smaller pyramids but that only became annoying while switching between 2 perks, 1 perk or even 1/2 a perk (jump boost vs. jump boost II for example).
And I'm too lazy to rebuild such a big pyramid on all corners (I play vanilla here). But a solution to that problem has now been found!
Save your work using structure blocks!
It's really very simple: place a structure block outside of the structure which you want to save. By default this will be a data block, but we'll need a 'save' block. So right click to open the interface, and click the mode button (lower left corner) to change it:
Structure block interface, the 'mode button' is highlighted.
Now we need to specify 2 coordinates: first the starting position and then the end position. So both corners of the structure which we want to save. I'm going to save a beacon pyramid, which is 10x9 blocks wide and 6 blocks high (4 blocks for the pyramid, 1 for the beacons and 1 for the yellow glass on top).
Important: the first coordinate will be relative to the position of the structure block. Also note that the structure block cannot cope with negative size values, so the coordinates of the starting point are always lower than the end point:
The structure (save) block is in the lower right corner of the screen (on the ground). But if you look at the crosshair you'll see that the pyramid sits within a negative X and Z range. Now look closely at the left side of the beacons: you'll see a vertical green line. This is part of the box surrounding the pyramid and it indicates where the starting point of the structure block is set. The box shows us which area is going to be saved by the structure block.
You can probably see where this is going: the only thing I have to do is to make sure that the box covers my whole structure, and then I merely have to click 'SAVE'.
Now, working with coordinates has become second nature for me, but even so I still manage to make mistakes from time to time. So what to do if all those coordinates only confuse you to no end?
Simple: then all you do is place corner blocks in 2 opposite corners of your structure and give them the same name, place the save block outside of your structure and give this the same name as well, then click detect. Now the 'save box' will be generated for you automatically:
Look closely: there's one corner block between the chest and the structure block (on the ground), the other can be seen floating in the air (in the center of the picture).
So how do we make sure that the box fully encloses our structure? Simple: use the hidden blocks!
Hidden blocks & structure void blocks!
Did you know that air blocks are blocks too? Now you do So if you enable the option "show invisible blocks" then this is going to happen:
See the blue boxes? Those indicate air blocks, can you spot the error here?
Look closely at the picture above and you'll see that I made an error. The extension is 2 blocks wide, but only 1 layer of blue boxes show (see left side). This can really help you to determine the right size of your 'save box' because all invisible air blocks are now shown.
But there's more...
Air blocks are real blocks even though you can't see them. So if you save a structure then those air blocks will replace any other blocks when you load the structure again. Unless you can somehow remove those air blocks... And that can be done using the structure void blocks.
We all know the void, right? Go beyond the bedrock floor and you'll end up in the void, like this:
A structure void block is exactly that: it's a block like the void: it represents nothing. And unlike an air block it also won't replace any other block when you load a structure again. I'll show you in the last part of this tutorial
Loading / placing structures
First you place a load block, you do this in the same way as shown above: place a structure block, open the interface and click the 'mode button' until it says "[L]" (for load). Then type the name of the structure you want to load, enter the starting coordinates and click "LOAD":
I entered the name and starting coordinates, now I'm going to click LOAD
After clicking LOAD for the first time you'll first see a box which highlights the destination
This is basically all there is to it. The number buttons and the | labeled button allow you to rotate and mirror your structure, after you click on them the highlight box will show you exactly what's going to happen. Once you're satisfied then all which is left to do is click the LOAD button again and your new structure will be placed.
But things can become really exciting when you hook these blocks up with some redstone
Here I set up a structure load block and made sure that the highlight box isn't shown. I placed a pressure plate which triggers both the command block below it and the structure load block. Please ignore the command block on top of the glass, I only use that to clean things up again
So, when I step onto the pressure plate then this suddenly happens:
Can you imagine all the stuff which you can do in adventure maps?
So yeah... A quick guide on structure blocks
In short: the Minecraft jar file contains a 'structures' directory (assets\minecraft\structures) which in its turn contains endcity, fossils and igloo. The upcoming 1.11 (currently only available as snapshot) adds mansion to this list. As a result the only pre-made (official Minecraft) structures which you can load are the endcity (towers and endship), the different fossils as well as the igloo.
If you want to load in an endship you'd use: endcity/ship as the name in the structure load block, but for more detailed information I'd like to refer you to that link (structure block tutorial).